Heat Pump Energy Supply Optimization Method and System

ABSTRACT

A method of optimizing a heat pump energy supply, comprising: sensing the ambient temperature; and responsive to the sensed ambient temperature, selecting one of a first energy source and a second energy source to provide energy for processing a working fluid of the heat pump, the second energy source different than the first energy source.

TECHNICAL FIELD

The present disclosure relates generally to the field of airconditioning and in particular to a system and method for optimizing theenergy usage of a heat pump utilizing a combination of waste heat,electric powered heat and combustible material powered heat.

BACKGROUND

Heat pumps operate by extracting heat from outdoor ambient air, andtransferring that heat to a climate controlled area, such as a home orbusiness. In a cooling mode, heat pumps operate by extracting heat fromthe air of the climate controlled area into the ambient air. In aheating mode, heat pumps operate by extracting heat from the outsideambient air and passing the heat into the climate controlled area. Heatpumps are generally more economical to operate than conventionalfurnaces that burn fossil fuels. However, the coefficient of performance(COP) of the heat pump is a function of the ambient air temperature.During a heating cycle, as the ambient temperature decreases the COP ofthe heat pump will decrease, since more work is necessary to extract theheat from the ambient air. During the heating cycle, at a certain pointthe COP becomes too small to be considered economically efficient incomparison to a furnace or other fossil fuel heating source.

One typical solution is to provide a backup heater to the heat pump,such that when the ambient temperature becomes too low, the heat pumpwill cease operation and a heater, such as a gas or electric radiator,will provide heat to the climate controlled environment. Unfortunately,this adds cost and complexity since two separate systems are needed, aheat pump and a heater. Additionally, the additional heater does notnecessarily provide the most energy efficient form of heating. Moreover,typically such double systems are not able to switch between the heatpump and additional heater within an appropriate time frame to allow foran economical control of the desired target temperature of the climatecontrolled area. Furthermore, such a system provides no method foroptimizing the energy consumption of the heat pump during a coolingcycle.

Additionally, many industrial processes produce waste heat of lowtemperature, typically less than 150° C., which is typically too low tobe used to accomplish useful work. Certain thermodynamic cycles, such asabsorption refrigeration, can provide environmental cooling and heatingfrom low grade heat sources. Similarly, solar thermal energy received ina solar collector such as a concentrating type or an evacuated tube typeis typically of the order of waste heat, and has been employed inabsorption chillers to provide environmental cooling. Unfortunately, theabsorption refrigeration cycles typically used suffer from inefficiency,and are typically unable to achieve a COP greater than about 0.7, wherethe term COP is defined as Δ/ΔW, where ΔQ is defined as theheating/cooling load change and ΔW is defined as the work consumed bythe cooling system. Other types of heat pumps achieve a greater COP,however the energy output of the waste/solar heat source is not alwayssufficient to power such a heat pump.

What is desired is a method and system for optimizing the energy supplyof a heat pump, so that the cost of operation of the heat pump will becontinuously maintained at a minimum for a wide range of ambient airtemperatures.

SUMMARY OF INVENTION

In view of the discussion provided above and other considerations, thepresent disclosure provides methods and apparatus to overcome some orall of the disadvantages of prior and present methods of energy supplyoptimization of heat pumps. Other new and useful advantages of thepresent methods and apparatus will also be described herein and can beappreciated by those skilled in the art.

In an exemplary embodiment, a heat pump apparatus is provided, the heatpump apparatus comprising: a control circuitry; a first energy sourceinput port arranged to receive energy from a first energy source; asecond energy source input port arranged to receive energy from a secondenergy source, the second energy source different than the first energysource, each of the first and second energy source input ports arrangedto provide energy for processing a working fluid contained within theheat pump apparatus, responsive to the control circuitry; and an ambienttemperature sensor in communication with the control circuitry, theambient temperature sensor arranged to sense the temperature of theambient air, wherein the control circuitry is arranged to alternatelyselect one of the first energy source input port and the second energysource input port to provide energy for processing the working fluid,the selection responsive to the sensed ambient air temperature.

In one embodiment, the control circuitry is arranged to determine therequired energy output from each of the first energy source and thesecond energy source to provide energy for processing the single workingfluid, responsive to the sensed ambient temperature, and wherein thecontrol circuitry is arranged to determine the cost of operation of theheat pump apparatus by each of the first energy source and the secondenergy source responsive to the determined required energy output, theselection performed responsive to the determined cost of operation. Inanother embodiment, the first energy source comprises a source ofelectricity and the second energy source comprises a combustiblematerial powered water heater. In one further embodiment, the heat pumpapparatus further comprises: a compressor in electrical communicationwith the first energy source input port, the compressor arranged tocompress the working fluid; and a heat exchanger in thermalcommunication with the second energy source input port, the heatexchanger arranged to transfer heat from the combustible materialpowered water heater to the working fluid.

In one embodiment, the heat pump apparatus further comprises a thirdenergy source input port arranged to receive energy from a third energysource, different that the first and second energy sources, the thirdenergy source input port arranged to provide energy for processing theworking fluid, wherein the control circuitry is further arranged todetermine the energy output of the third energy source, the selectionperformed only in the event that the determined energy output of thethird energy source is less than the energy requirements of the heatpump apparatus. In one further embodiment, the third energy sourcecomprises one of a waste heat source and a solar water heater.

In one yet further embodiment, the heat pump apparatus further comprisesa heat exchanger in thermal communication with: the second energy sourceinput port; and the third energy source input port. In another furtherembodiment, the arrangement of the third energy source input to provideenergy for processing the working fluid is responsive to the controlcircuitry, wherein in the event that the determined energy output of thethird energy source is less than the energy requirements of the heatpump apparatus, the control circuitry is further arranged to control thethird energy source input port to provide energy for processing theworking fluid.

In one independent embodiment, a method of optimizing a heat pump energysupply is provided, the method comprising: sensing the ambienttemperature; responsive to the sensed ambient temperature, selecting oneof a first energy source and a second energy source to provide energyfor processing a working fluid of the heat pump, the second energysource different than the first energy source.

In one embodiment, the method further comprises: determining therequired energy output from each of the first energy source and thesecond energy source to provide energy for processing the working fluid,responsive to the sensed ambient temperature; and determining the costof operation of the heat pump by each of the first energy source and thesecond energy source responsive to the determined required energyoutput, the selecting performed responsive to the determined cost ofoperation. In another embodiment, the first energy source comprises asource of electricity and the second energy source comprises acombustible material powered water heater. In one further embodiment,the selecting the first energy source comprises providing electric powerfrom the source of electricity to a compressor, wherein the selectingthe second energy source comprises providing heat from the combustiblematerial powered water heater to a heat exchanger.

In one embodiment, the method further comprises determining the energyoutput of a third energy source, the third energy source different thatthe first and second energy sources, the selecting performed only in theevent that the determined energy output of the third energy source isless that the energy requirements of the heat pump. In one furtherembodiment, the third energy source comprises one of a waste heat sourceand a solar water heater.

In one yet further embodiment, the method further comprises providingheat from the output of the second and third energy sources to a heatexchanger. In another embodiment, the method further comprises in theevent that the determined energy output of the third energy source isless than the energy requirements of the heat pump, providing energyoutput from the third energy source for processing the working fluid.

In another independent embodiment, a non-transitory computer readablemedium having instructions stored thereon is provided, which, whenexecuted by one or more processors, causes the one or more processors toperform operations, the operations comprising: sensing the ambienttemperature; and responsive to the sensed ambient temperature, selectingone of a first energy source and a second energy source to provideenergy for processing a working fluid of the heat pump, the secondenergy source different than the first energy source.

In one embodiment, the operations further comprise: determining therequired energy output from each of the first energy source and thesecond energy source to provide energy for processing the working fluid,responsive to the sensed ambient temperature; and determining the costof operation of the heat pump by each of the first energy source and thesecond energy source responsive to the determined required energyoutput, the selecting performed responsive to the determined cost ofoperation. In another embodiment, the first energy source comprises asource of electricity and the second energy source comprises acombustible material powered water heater. In one further embodiment,the selecting the first energy source comprises providing electric powerfrom the source of electricity to a compressor, and wherein theselecting the second energy source comprises providing heat from thecombustible material powered water heater to a heat exchanger.

In one embodiment, the operations further comprise determining theenergy output of a third energy source, the third energy sourcedifferent that the first and second energy sources, the selectingperformed only in the event that the determined energy output of thethird energy source is less that the energy requirements of the heatpump. In one further embodiment, the third energy source comprises oneof a waste heat source and a solar water heater.

In one yet further embodiment, the operations further comprise providingheat from the output of the second and third energy sources to a heatexchanger. In another further embodiment, the operations furthercomprise, in the event that the determined energy output of the thirdenergy source is less than the energy requirements of the heat pump,providing energy output from the third energy source for processing theworking fluid.

Additional features and advantages of the invention will become apparentfrom the following drawings and description.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the invention and to show how the same maybe carried into effect, reference will now be made, purely by way ofexample, to the accompanying drawings in which like numerals designatecorresponding elements or sections throughout.

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of the preferred embodiments of the presentinvention only, and are presented in the cause of providing what isbelieved to be the most useful and readily understood description of theprinciples and conceptual aspects of the invention. In this regard, noattempt is made to show structural details of the invention in moredetail than is necessary for a fundamental understanding of theinvention, the description taken with the drawings making apparent tothose skilled in the art how the several forms of the invention may beembodied in practice. In the accompanying drawings:

FIG. 1A illustrates a high level schematic diagram of a heat pumpapparatus, according to certain embodiments;

FIG. 1B illustrates a high level schematic diagram of a heat pumpapparatus, comprising a compressor and a heat exchanger, according tocertain embodiments;

FIG. 1C illustrates a high level schematic diagram of a controlcircuitry of the heat pump apparatuses of FIGS. 1A-1B;

FIG. 2 illustrates a high level flow chart of a method of operation ofthe heat pump apparatus of FIG. 1B in a heating cycle, according tocertain embodiments; and

FIG. 3 illustrates a high level flow chart of a method of operation ofthe heat pump apparatus of FIG. 1B in a cooling cycle, according tocertain embodiments.

DESCRIPTION OF EMBODIMENTS

Before explaining at least one embodiment in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction and the arrangement of the components set forthin the following description or illustrated in the drawings. Theinvention is applicable to other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting. In particular, theterm connected as used herein is not meant to be limited to a directconnection, and allows for intermediary devices or components withoutlimitation.

FIG. 1A illustrates a high level schematic diagram of a heat pumpapparatus 10, according to certain embodiments. Heat pump apparatus 10comprises: an external unit 20; an internal unit 30; a combustiblematerial driven heat energy source 40; and an electric energy source 50.External unit 20 comprises: a combustible material driven energy sourceinput port 60; an electric energy source input port 70; a controlcircuitry 80; a heat driven heat pump sub-system 90; an electric drivenheat pump sub-system 100; and an ambient temperature sensor 110.

External unit 20 is positioned outside a climate controlled area 120 andinternal unit 30 is positioned within climate controlled area 120.External unit 20 is in fluidic communication with internal unit 30 suchthat working fluid of heat pump apparatus 10, such as refrigerant, istransferred bi-directionally between external unit 20 and internal unit30. In one embodiment, power is supplied from external unit 20 tointernal unit 30 and internal unit 30 is further in communication withcontrol circuitry 80 of external unit 20. Heat pump apparatus 10 isillustrated and described as comprising an internal unit 30 and anexternal unit 20, however this is not meant to be limiting in any wayand a heat pump apparatus comprising only an internal unit iscontemplated without exceeding the scope.

In one embodiment, combustible material driven energy source 40comprises a water heater, optionally heated by burning any of naturalgas, liquid petroleum gas, diesel combustible material and heating oil,without limitation. The output of combustible material driven energysource 40 is coupled to heat driven heat pump sub-system 90, viacombustible material driven energy source input port 60 of external unit20, and is arranged to provide heat thereto. Electric energy source 50is coupled to electric driven heat pump sub-system 100, via electricenergy source input port 70, and is arranged to provide electricitythereto. In one embodiment, electric energy source 50 comprises anelectric mains power supply. Ambient temperature sensor 110 is arrangedto sense the temperature of the ambient air surrounding external unit20. Heat driven heat pump sub-system 90 and electric driven heat pumpsub-system 100 are illustrated as separate units, however this is notmeant to be limiting in any way and heat pump apparatus 10 isparticularly contemplated with heat driven heat pump sub-system 90 andelectric driven heat pump sub-system 100 being integrated within asingle system, each arranged to process a common working fluid toprovide heating/cooling.

Heat driven heat pump sub-system 90 and electric driven heat pumpsub-system 100 are arranged to provide heating/cooling via internal unit30 to adjust the temperature in climate controlled area 120. A workingliquid, such as a refrigerant, is provided within external unit 20. Inone further embodiment, heat driven heat pump sub-system 90 and electricdriven heat pump sub-system 100 are each arranged to provide compressionand expansion of the working fluid in order to provide heating/cooling,as known to those skilled in the art. In another further embodiment,heat driven heat pump sub-system 90 and electric driven air conditioningsub-system 100 are each arranged to provide an absorption cycleutilizing a water-ammonia mixture in order to provide heating/cooling,as known to those skilled in the art. In another embodiment, heat drivenheat pump sub-system 90 and electric driven air conditioning sub-system100 are arranged to provide heating/cooling as described in U.S. PatentApplication Publication S/N 2012/0023982 to Berson et al., ofpublication date Feb. 2, 2012, the entire contents of which areincorporated herein by reference. As described therein, heat driven heatpump sub-system 90 and electric driven air conditioning sub-system 100comprise an integrated single unit.

Control circuitry 80 is in communication with heat driven heat pumpsub-system 90, electric driven heat pump sub system 100 and ambienttemperature sensor 110. In one embodiment, control circuitry 80 isfurther in communication with combustible material driven energy sourceinput port 60 and electric energy source input port 70. In another,optionally alternate, embodiment, control circuitry 80 is incommunication with combustible material driven energy source 40 andelectric energy source 50.

In operation, as will be described further below, control circuitry 80is arranged to receive from ambient temperature sensor 110 the sensedtemperature of the ambient air. Responsive to the received temperature,control circuitry 80 is arranged to determine the energy requirements ofeach of heat driven heat pump sub-system 90 and electric driven heatpump sub-system 100 to adjust the temperature of the air within climatecontrolled area 120 to a desired target temperature. Control circuitry80 is further arranged to determine the monetary cost of the abovedetermined energy requirements. Control circuitry 80 is further arrangedto select and operate a particular one of heat driven heat pumpsub-system 90 and electric driven heat pump sub system 100, theselection performed responsive to the determination of the energyrequirements exhibiting the least monetary cost. Advantageously, asingle heat pump 10, optionally with a single working fluid, and with asingle internal unit 30, is alternately operated by two different energysources, responsive to the monetary cost thereof.

FIG. 1B illustrates a high level schematic diagram of a heat pumpapparatus 200, according to certain embodiments. Heat pump apparatus 200comprises: an external unit 220; an internal unit 30; a combustiblematerial driven energy source 40; an electric energy source 50; and asolar/waste heat source 230. External unit 220 comprises: a combinedcombustible material driven energy source and solar/waste heat sourceinput port 170; an electric energy source input port 70; a controlcircuitry 80; a heat driven heat pump sub-system 250, comprising a heatexchanger 260; an electric driven heat pump sub-system 270, comprising acompressor 280; and an ambient temperature sensor 110. Solar/waste heatsource 230 in one embodiment comprises one or more solar panels. Inanother embodiment, solar/waste heat source 230 comprises a waste heatsource.

External unit 220 is positioned outside climate controlled area 120 andinternal unit 30 is positioned within climate controlled area 120, asdescribed above in relation to heat pump apparatus 10 of FIG. 1A.External unit 220 is in fluidic communication with internal unit 30 suchthat working fluid of heat pump apparatus 200, such as refrigerant, istransferred bi-directionally between external unit 220 and internal unit30. In one embodiment, power is supplied from external unit 220 tointernal unit 30 and internal unit 30 is further in communication withcontrol circuitry 80 of external unit 220. Heat pump apparatus 200 isillustrated and described as comprising an internal unit 30 and anexternal unit 220, however this is not meant to be limiting in any wayand a heat pump apparatus comprising only an internal unit iscontemplated without exceeding the scope.

The output of combustible material driven heat energy source 40 iscoupled to heat driven heat pump sub-system 250, via combustiblematerial driven energy source input port 60 of external unit 220, and isarranged to provide heat thereto. Electric energy source 50 is coupledto electric driven heat pump sub-system 270, via electric energy sourceinput port 70, and is arranged to provide electricity thereto.

Solar/waste heat source 230 is coupled to heat driven heat pumpsub-system 250, via combustible material driven energy source input port60, and is arranged to provide heat thereto. Solar/waste heat source isin thermal communication with heat driven heat pump sub-system 250, andin particular to heat exchanger 260 thereof. In another embodiment,combustible material driven energy source 40 and solar/waste heat source230 are both arranged to provide hot water to heat exchanger 260 of heatdriven heat pump sub-system 250. Heat pump apparatus 200 is illustratedwhere combustible material driven energy source 40 and solar/waste heatsource 230 are arranged in a serial formation, however this is not meantto be limiting in any way. In another embodiment, combustible materialdriven energy source 40 and solar/waste heat source 230 can be thermallycoupled to heat driven heat pump sub-system 250 in a parallelconfiguration, without exceeding the scope. In one embodiment, heatexchanger 260 is arranged to transfer heat from the received hot waterto the working fluid of heat pump apparatus 200, such as a refrigerant.Compressor 280 of electric driven heat pump sub-system 270 is arrangedto provide a vapor compression cycle for the operation liquid of heatpump apparatus 200.

Heat driven heat pump sub-system 250 and electric driven heat pumpsub-system 270 are illustrated as separate units, however this is notmeant to be limiting in any way and heat pump apparatus 200 isparticularly contemplated with heat driven heat pump sub-system 250 andelectric driven heat pump sub-system 270 being integrated within asingle system, each arranged to process a common working fluid toprovide heating/cooling.

Control circuitry 80 is in communication with heat driven heat pumpsub-system 250, electric driven heat pump sub-system 270 and ambienttemperature sensor 110. In one embodiment, control circuitry 80 isfurther in communication with combustible material driven energy sourceinput port 60 and electric energy source input port 70. In another,optionally alternate, embodiment, control circuitry 80 is incommunication with combustible material driven energy source 40 andelectric energy source 50.

In operation, control circuitry 80 is arranged to determine the energyoutput of solar/waste heat source 230. In one embodiment, the energyoutput is determined by sensing the temperature output of solar/wasteheat source 230. In the event that control circuitry 80 determines thatthe energy output of solar/waste heat source 230 is less than the energyneeded for heat pump apparatus 200 to adjust the temperature of climatecontrolled area 120 to the desired temperature, control circuitry 80 isarranged to select one of heat driven heat pump sub-system 250 andelectric driven heat pump sub-system 270, as described above in relationto heat pump apparatus 10 of FIG. 1A. In one embodiment, as will bedescribed below, in the event that control circuitry 80 selects heatdriven heat pump sub-system 250, both combustible material driven energysource 40 and solar/waste heat source 230 provide power thereto. In theevent that control circuitry 80 selects electric driven heat pumpsub-system 270, control circuitry 80 is further arranged, in parallel,to control heat driven heat pump sub-system 250 to provideheating/cooling with power being provided by solar/waste heat source230. Thus, both heat driven heat pump sub-system 250 and electric drivenheat pump sub-system 270 provide heating to climate controlled area 120.

FIG. 1C illustrates a high level block diagram of control circuitry 80of heat pump apparatus 10 of FIG. 1A and heat pump apparatus 200 of FIG.1B. Control circuitry 80 comprises: a solar/waste heat energy outputdetermination functionality 290; an energy consumption determinationfunctionality 300, arranged to determine the energy consumption of eachof combustible material driven energy source 40 and electric energysource 50, as will be described below; a monetary cost determinationfunctionality 310, arranged to determine the monetary cost of operatingheat driven heat pump sub-systems 90 and 250, and electric driven heatpump sub-systems 100 and 270, as will be described below; a selectionfunctionality 320, arranged to select one or more of heat driven heatpump sub-systems 90 and 250, and electric driven heat pump sub-systems100 and 270 to operate the respective one of heat pumps 10 and 200, aswill be described below. Solar/waste heat energy output determinationfunctionality 290, energy consumption determination functionality 300,monetary cost determination functionality 310 and selectionfunctionality 320 can each be implemented by any of: a dedicatedfunctionality; computer readable instructions for a general purposecomputing device or processor, the readable instructions stored on amemory 330 and arranged to be run by a processor 340; dedicatedhardware; and a dedicated control circuitry, without limitation.

FIG. 2 illustrates a high level flow chart of a method of operation ofheat pump apparatus 200 of FIG. 1B in a heating cycle, according tocertain embodiments. In stage 1000, control circuitry 80 is arranged toreceive a temperature reading of the temperature within climatecontrolled area 120 and the desired temperature, from internal unit 30.In stage 1010, control circuitry 80 is arranged to determine therequired heating load to bring the temperature of climate controlledarea 120 to the desired temperature. The term ‘determine’ is not meantto be limited to an exact determination and is particularly meant toinclude an approximation. In stage 1020, solar/waste heat energy outputdetermination functionality 290 of control circuitry 80 is arranged todetermine the energy output of solar/waste heat source 230. Optionally,the energy output is determined by sensing the output temperature of theheat of solar/waste heat source 230, optionally by sensing thetemperature of the heat supply fluid of the combined combustiblematerial driven energy source 40 and solar/waste heat source input port170 and flow.

In stage 1030, selection functionality 320 is arranged to compare thedetermined energy output of solar/waste heat source 230 of stage 1020with the determined required heating load of stage 1010. In the eventthat the determined energy output of solar/waste heat source 230 is lessthan required heating load, in stage 1040 energy consumptiondetermination functionality 300 is arranged to receive the sensedambient temperature from ambient temperature sensor 110.

In stage 1050, energy consumption determination functionality 300 isarranged to determine the required energy consumption of each of heatdriven heat pump sub-system 250 and electric driven heat pump sub-system270 to provide the determined heating load of stage 1010, the requiredenergy consumption determined responsive to the sensed ambienttemperature of stage 1040. In particular, energy consumptiondetermination functionality 300 is arranged to determine how much energywould need to be produced from each of combustible material drivenenergy source 40 and electric energy source 50 to power heat pumpapparatus 200, optionally after subtracting the provided energy fromsolar/waste heat source 230, as will be described below. In oneembodiment, the required energy consumption is determined responsive toa pre-measured function of the operation of each of heat driven heatpump sub-system 250 and electric driven heat pump sub-system 270 for oneor more measured ambient temperatures. In another embodiment, therequired energy consumption is determined responsive to a lookup tablecomprising measured energy requirements of each of heat driven heat pumpsub-system 250 and electric driven heat pump sub-system 270 for aplurality of ambient temperature ranges. In another embodiment, therequired energy consumption is determined responsive to knownthermodynamic properties of heat driven heat pump sub-system 250 andelectric driven heat pump sub-system 270. Optionally, the requiredenergy consumption is determined only for the portion of the heatingload which cannot sufficiently be supplied by solar/waste heat source230.

In stage 1060, monetary cost determination functionality 310 of controlcircuitry 80 is arranged to determine the monetary cost of operation foreach of heat driven heat pump sub-system 250 and electric driven heatpump sub-system 270. In particular, the determined required energyconsumption of stage 1050 is multiplied by the monetary cost per unit ofthe combustible material of combustible material driven energy source 40and of electricity. Optionally, the monetary cost per unit isperiodically updated.

In stage 1070, selection functionality 320 is arranged to determinewhich of heat driven heat pump sub-system 250 and electric driven heatpump sub-system 270 is cheaper to operate. In stage 1080, selectionfunctionality 320 is arranged to select the one of heat driven heat pumpsub-system 250 and electric driven heat pump sub-system 270 which ischeaper to operate, and control the selected sub-system to provide thedesired heating cycle. Thus, the most economically efficient energysource is utilized to provide energy to process the working fluid ofheat pump apparatus 200. Optionally, heat driven heat pump sub-system250 is continuously operated by the energy output of solar/waste heatsource 230 and is supplemented by either: electric driven heat pumpsub-system 270; or the addition of the heat energy output of combustiblematerial driven energy source 40 to heat driven heat pump sub-system250.

In the event that in stage 1030 selection functionality 320 determinesthat the energy output of solar/waste heat source 230 is sufficient forthe required heating load, in stage 1090 heat driven heat pumpsub-system 250 is operated by the energy output of solar/waste heatsource 230, thereby operating heat pump apparatus 200.

FIG. 3 illustrates a high level flow chart of a method of operation ofheat pump apparatus 200 of FIG. 1B in a cooling cycle, according tocertain embodiments. In stage 2000, control circuitry 80 is arranged toreceive a temperature reading of the temperature within climatecontrolled area 120 and the desired temperature, from internal unit 30.In stage 2010, control circuitry 80 is arranged to determine therequired cooling load to bring the temperature of climate controlledarea 120 to the desired temperature. In stage 2020, solar/waste heatenergy output determination functionality 290 of control circuitry 80 isarranged to determine the energy output of solar/waste heat source 230.Optionally, the energy output is determined by sensing the outputtemperature of the heat of solar/waste heat source 230.

In stage 2030, selection functionality 320 is arranged to compare thedetermined energy output of solar/waste heat source 230 of stage 2020with the determined required cooling load of stage 2010. In the eventthat the determined energy output of solar/waste heat source 230 is lessthan required cooling load, in stage 2040, energy consumptiondetermination functionality 300 is arranged to determine the requiredenergy consumption of each of heat driven heat pump sub-system 250 andelectric driven heat pump sub-system 270 to provide the determinedcooling load of stage 2010. In particular, energy consumptiondetermination functionality 300 is arranged to determine how much energywould need to be produced from each of combustible material drivenenergy source 40 and electric energy source 50 to power heat pumpapparatus 200. Optionally, the required energy consumption is determinedonly for the portion of the cooling load which cannot sufficiently besupplied by solar/waste heat source 230.

In stage 2050, monetary cost determination functionality 310 of controlcircuitry 80 is arranged to determine the monetary cost of operation foreach of heat driven heat pump sub-system 250 and electric driven heatpump sub-system 270. In particular, the determined required energyconsumption of stage 1050 is multiplied by the monetary cost per unit ofthe combustible material of combustible material driven energy source 40and of electricity. Optionally, the monetary cost per unit isperiodically updated.

In stage 2060, selection functionality 320 is arranged to determinewhich of heat driven heat pump sub-system 250 and electric driven heatpump sub-system 270 is cheaper to operate. In stage 2070, selectionfunctionality 320 is arranged to select the one of heat driven heat pumpsub-system 250 and electric driven heat pump sub-system 270 which ischeaper to operate, and control the selected sub-system to provide thedesired cooling cycle. Thus, the most economically efficient energysource is utilized to provide energy to process the working fluid ofheat pump apparatus 200. Optionally, heat driven heat pump sub-system250 is continuously operated by the energy output of solar/waste heatsource 230 and is supplemented by either: electric driven heat pumpsub-system 270; or the addition of the heat energy output of combustiblematerial driven energy source 40 to heat driven heat pump sub-system250.

In the event that in stage 2030 selection functionality 320 determinesthat the energy output of solar/waste heat source 230 is sufficient forthe required cooling load, in stage 2070 heat driven heat pumpsub-system 250 is operated by the energy output of solar/waste heatsource 230, thereby operating heat pump apparatus 200.

The method of operation of heat pump apparatus 10 of FIG. 1A is in allrespects similar to the method of operation of heat pump apparatus 200of FIG. 1B described above, with the exception that solar/waste heatsource 230 is not provided. Thus, in the interest of brevity, the methodof operation thereof will not be further described.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meanings as are commonly understood by one of ordinaryskill in the art to which this invention belongs. Although methodssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods aredescribed herein.

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety. Incase of conflict, the patent specification, including definitions, willprevail. In addition, the materials, methods, and examples areillustrative only and not intended to be limiting.

The terms “include”, “comprise” and “have” and their conjugates as usedherein mean “including but not necessarily limited to”. The term“connected” is not limited to a direct connection, and connection viaintermediary devices is specifically included.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather the scope of the present invention isdefined by the appended claims and includes both combinations andsub-combinations of the various features described hereinabove as wellas variations and modifications thereof, which would occur to personsskilled in the art upon reading the foregoing description.

We claim:
 1. A heat pump apparatus comprising: a control circuitry; a first energy source input port arranged to receive energy from a first energy source; a second energy source input port arranged to receive energy from a second energy source, the second energy source different than the first energy source, each of the first and second energy source input ports arranged to provide energy for processing a working fluid contained within the heat pump apparatus, responsive to the control circuitry; and an ambient temperature sensor in communication with the control circuitry, the ambient temperature sensor arranged to sense the temperature of the ambient air, wherein the control circuitry is arranged to alternately select one of the first energy source input port and the second energy source input port to provide energy for processing the working fluid, the selection responsive to the sensed ambient air temperature.
 2. The heat pump apparatus of claim 1, wherein the control circuitry is arranged to determine the required energy output from each of the first energy source and the second energy source to provide energy for processing the single working fluid, responsive to the sensed ambient temperature, and wherein the control circuitry is arranged to determine the cost of operation of the heat pump apparatus by each of the first energy source and the second energy source responsive to the determined required energy output, the selection performed responsive to the determined cost of operation.
 3. The heat pump apparatus of claim 1, wherein the first energy source comprises a source of electricity and the second energy source comprises a combustible material powered water heater.
 4. The heat pump apparatus of claim 3, further comprising: a compressor in electrical communication with the first energy source input port, the compressor arranged to compress the working fluid; and a heat exchanger in thermal communication with the second energy source input port, the heat exchanger arranged to transfer heat from the combustible material powered water heater to the working fluid.
 5. The heat pump apparatus of claim 1, further comprising a third energy source input port arranged to receive energy from a third energy source, different that the first and second energy sources, the third energy source input port arranged to provide energy for processing the working fluid, wherein the control circuitry is further arranged to determine the energy output of the third energy source, the selection performed only in the event that the determined energy output of the third energy source is less than the energy requirements of the heat pump apparatus.
 6. The heat pump apparatus of claim 5, wherein the third energy source comprises one of a waste heat source and a solar water heater.
 7. The heat pump apparatus of claim 6, further comprising a heat exchanger in thermal communication with: the second energy source input port; and the third energy source input port.
 8. The heat pump apparatus of claim 5, wherein the arrangement of the third energy source input to provide energy for processing the working fluid is responsive to the control circuitry, and wherein in the event that the determined energy output of the third energy source is less than the energy requirements of the heat pump apparatus, the control circuitry is further arranged to control the third energy source input port to provide energy for processing the working fluid.
 9. A method of optimizing a heat pump energy supply, the method comprising: sensing the ambient temperature; and responsive to the sensed ambient temperature, selecting one of a first energy source and a second energy source to provide energy for processing a working fluid of the heat pump, the second energy source different than the first energy source.
 10. The method of claim 9, further comprising: determining the required energy output from each of the first energy source and the second energy source to provide energy for processing the working fluid, responsive to the sensed ambient temperature; and determining the cost of operation of the heat pump by each of the first energy source and the second energy source responsive to the determined required energy output, the selecting performed responsive to the determined cost of operation.
 11. The method of claim 9, wherein the first energy source comprises a source of electricity and the second energy source comprises a combustible material powered water heater.
 12. The method of claim 11, wherein the selecting the first energy source comprises providing electric power from the source of electricity to a compressor, and wherein the selecting the second energy source comprises providing heat from the combustible material powered water heater to a heat exchanger.
 13. The method of claim 9, further comprising determining the energy output of a third energy source, the third energy source different that the first and second energy sources, the selecting performed only in the event that the determined energy output of the third energy source is less that the energy requirements of the heat pump.
 14. The method of claim 13, wherein the third energy source comprises one of a waste heat source and a solar water heater.
 15. The method of claim 14, further comprising providing heat from the output of the second and third energy sources to a heat exchanger.
 16. The method of claim 13, further comprising, in the event that the determined energy output of the third energy source is less than the energy requirements of the heat pump, providing energy output from the third energy source for processing the working fluid.
 17. A non-transitory computer readable medium having instructions stored thereon, which, when executed by one or more processors, causes the one or more processors to perform operations, the operations comprising: sensing the ambient temperature; and responsive to the sensed ambient temperature, selecting one of a first energy source and a second energy source to provide energy for processing a working fluid of the heat pump, the second energy source different than the first energy source.
 18. The non-transitory computer readable medium of claim 17, wherein the operations further comprise: determining the required energy output from each of the first energy source and the second energy source to provide energy for processing the working fluid, responsive to the sensed ambient temperature; and determining the cost of operation of the heat pump by each of the first energy source and the second energy source responsive to the determined required energy output, the selecting performed responsive to the determined cost of operation.
 19. The non-transitory computer readable medium of claim 17, wherein the first energy source comprises a source of electricity and the second energy source comprises a combustible material powered water heater.
 20. The non-transitory computer readable medium of claim 19, wherein the selecting the first energy source comprises providing electric power from the source of electricity to a compressor, and wherein the selecting the second energy source comprises providing heat from the combustible material powered water heater to a heat exchanger.
 21. The non-transitory computer readable medium of claim 17, wherein the operations further comprise determining the energy output of a third energy source, the third energy source different that the first and second energy sources, the selecting performed only in the event that the determined energy output of the third energy source is less that the energy requirements of the heat pump.
 22. The non-transitory computer readable medium of claim 21, wherein the third energy source comprises one of a waste heat source and a solar water heater.
 23. The non-transitory computer readable medium of claim 22, wherein the operations further comprise providing heat from the output of the second and third energy sources to a heat exchanger.
 24. The non-transitory computer readable medium of claim 21, wherein the operations further comprise, in the event that the determined energy output of the third energy source is less than the energy requirements of the heat pump, providing energy output from the third energy source for processing the working fluid. 